| Message ID | 20220519122912.93536-1-marex@denx.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v3] drm/bridge: tc358767: Make sure Refclk clock are enabled | expand |
On Thu, May 19, 2022 at 02:29:12PM +0200, Marek Vasut wrote: > The Refclk may be supplied by SoC clock output instead of crystal > oscillator, make sure the clock are enabled before any other action > is performed with the bridge chip, otherwise it may either fail to > operate at all, or miss reset GPIO toggle. > > Reviewed-by: Lucas Stach <l.stach@pengutronix.de> > Fixes: 7caff0fc4296e ("drm/bridge: tc358767: Add DPI to eDP bridge driver") > Signed-off-by: Marek Vasut <marex@denx.de> > Cc: Jonas Karlman <jonas@kwiboo.se> > Cc: Laurent Pinchart <Laurent.pinchart@ideasonboard.com> > Cc: Lucas Stach <l.stach@pengutronix.de> > Cc: Marek Vasut <marex@denx.de> > Cc: Maxime Ripard <maxime@cerno.tech> > Cc: Neil Armstrong <narmstrong@baylibre.com> > Cc: Robert Foss <robert.foss@linaro.org> > Cc: Sam Ravnborg <sam@ravnborg.org> > --- > V2: - Use devm_add_action_or_reset() to add clock disable hook instead > of wall of failpath > V3: - Swap devm_add_action_or_reset()/clk_prepare_enable() to avoid > clock disable imbalance > - Add RB from Lucas > --- > drivers/gpu/drm/bridge/tc358767.c | 30 +++++++++++++++++++++++------- > 1 file changed, 23 insertions(+), 7 deletions(-) > > diff --git a/drivers/gpu/drm/bridge/tc358767.c b/drivers/gpu/drm/bridge/tc358767.c > index 45ea829d56601..7d4035ca26b19 100644 > --- a/drivers/gpu/drm/bridge/tc358767.c > +++ b/drivers/gpu/drm/bridge/tc358767.c > @@ -2033,6 +2033,13 @@ static int tc_probe_bridge_endpoint(struct tc_data *tc) > return -EINVAL; > } > > +static void tc_clk_disable(void *data) > +{ > + struct clk *refclk = data; > + > + clk_disable_unprepare(refclk); > +} > + > static int tc_probe(struct i2c_client *client, const struct i2c_device_id *id) > { > struct device *dev = &client->dev; > @@ -2049,6 +2056,22 @@ static int tc_probe(struct i2c_client *client, const struct i2c_device_id *id) > if (ret) > return ret; > > + tc->refclk = devm_clk_get(dev, "ref"); > + if (IS_ERR(tc->refclk)) { > + ret = PTR_ERR(tc->refclk); > + dev_err(dev, "Failed to get refclk: %d\n", ret); > + return ret; > + } > + > + clk_prepare_enable(tc->refclk); > + > + ret = devm_add_action_or_reset(dev, tc_clk_disable, tc->refclk); > + if (ret) > + return ret; We'll also have the imbalance if clk_prepare_enable fails. Maxime
diff --git a/drivers/gpu/drm/bridge/tc358767.c b/drivers/gpu/drm/bridge/tc358767.c index 45ea829d56601..7d4035ca26b19 100644 --- a/drivers/gpu/drm/bridge/tc358767.c +++ b/drivers/gpu/drm/bridge/tc358767.c @@ -2033,6 +2033,13 @@ static int tc_probe_bridge_endpoint(struct tc_data *tc) return -EINVAL; } +static void tc_clk_disable(void *data) +{ + struct clk *refclk = data; + + clk_disable_unprepare(refclk); +} + static int tc_probe(struct i2c_client *client, const struct i2c_device_id *id) { struct device *dev = &client->dev; @@ -2049,6 +2056,22 @@ static int tc_probe(struct i2c_client *client, const struct i2c_device_id *id) if (ret) return ret; + tc->refclk = devm_clk_get(dev, "ref"); + if (IS_ERR(tc->refclk)) { + ret = PTR_ERR(tc->refclk); + dev_err(dev, "Failed to get refclk: %d\n", ret); + return ret; + } + + clk_prepare_enable(tc->refclk); + + ret = devm_add_action_or_reset(dev, tc_clk_disable, tc->refclk); + if (ret) + return ret; + + /* tRSTW = 100 cycles , at 13 MHz that is ~7.69 us */ + usleep_range(10, 15); + /* Shut down GPIO is optional */ tc->sd_gpio = devm_gpiod_get_optional(dev, "shutdown", GPIOD_OUT_HIGH); if (IS_ERR(tc->sd_gpio)) @@ -2069,13 +2092,6 @@ static int tc_probe(struct i2c_client *client, const struct i2c_device_id *id) usleep_range(5000, 10000); } - tc->refclk = devm_clk_get(dev, "ref"); - if (IS_ERR(tc->refclk)) { - ret = PTR_ERR(tc->refclk); - dev_err(dev, "Failed to get refclk: %d\n", ret); - return ret; - } - tc->regmap = devm_regmap_init_i2c(client, &tc_regmap_config); if (IS_ERR(tc->regmap)) { ret = PTR_ERR(tc->regmap);